The ripple effects of the  worldwide flight ban of the Boeing 737 MAX continue to spread and cause financial harm. One day after Boeing Co. (NYSE:BA) declared that it would temporarily shut down the troubled plane's production line in January, Southwest Airlines (NYSE:LUV) said it is removing the MAX from its flight schedule through April 13.

In a Dec. 17 regulatory filing, Southwest said fourth quarter non-fuel costs were expected to increase 4% to 6% compared to the same period a year ago primarily because of the MAX groundings. Full-year passenger-related costs are projected to increase 8%. It said fuel efficiency is expected to decrease on a per passenger basis by 1% to 2%  because of the removal from service of the MAX, its most fuel-efficient plane. Passenger capacity is on track to dip 1% compared with the previous guidance of 0.5% to 1%. 

Southwest has 34 737 MAX 8 aircraft in its fleet that have been grounded by regulators since mid-March following two deadly overseas crashes blamed on poor design of the aircraft's automated flight control system and lack of pilot training with the system. In addition, the Dallas-based airline has 41 MAX aircraft on order from Boeing or aircraft leasing companies this year that have been delayed. Southwest previously adjusted its flight schedule through March 6.

As previously reported, Southwest reached an agreement for an undisclosed amount of compensation from Boeing related to operational and lost opportunity costs associated with the unavailability of the MAX. Southwest said it will give $125 million of that amount to its employees through its profit-sharing plan, and distribute it next quarter. It said it continues to negotiate for more compensation for damages related to the MAX grounding.

Airlines and their customers aren't the only ones feeling the pain from Boeing's problems with the MAX. The halt in MAX production will also reduce cash flow to hundreds of Boeing suppliers. Boeing said it is not laying off or furloughing any workers, but that could change the longer it takes for the airplane to get cleared for commercial service. Boeing is the nation's largest manufacturing exporter and any loss of cash flow throughout the supply chain could end up being felt by workers and the communities where they spend their money.